The proposed research will investigate the interaction of fluoride and cadmium, particularly in regard to the development of dental caries. This will be accomplished by presenting various fluoride-cadmium drinking solutions to rats and measuring the effect of cadmium on experimental dental caries and the cariostatic properties of fluoride. We will test if cadmium alters the uptake of fluoride into enamel, and if fluoride affects the deposition of cadmium in the hard and soft tissues of the rat. The incorporation of cadmium into the enamel matrix protein of rat teeth and how this is influenced by fluoride or zinc will be investigated. The proposed research will also test for correlations between the cadmium and fluoride concentrations in human enamel and their relations to dental caries. These studies will show how one environmental factor, cadmium, influences the development of dental caries.